Folding box



We W412. DE FOREST SACKETT I 2,2?7,717

FOLDING BOX FiledAug. 22, 1958 45heets-Sheet 1 v 'le f/lTTOQg 9 5 March 31, 142. DE FOREST SACKETT ,1

FOLDING BOX Filed Aug. 22, 1938 4 Sheets-Sheet 2 Bottom 10 O arch 31, 1942. DE FOREST SACKETT 2,277,717

FOLDING BOX Filed Aug. 22, 1938 4 Sheets-Sheet a a I r I m .Deyoresf LSQ'c/%e79" 3 $104M, ,L k. I

(ATTORNEYS March 31, 1942. DE FOREST s g -r 2,277,717

FOLDING BOX Filed Aug. 22, 1938 4 Sheets-Sheet 4 Bottom 1o 1 Elana 13 32 20 (d NVE NTORJ Dad owes f I Saaarf" Patented Mar. 31, 1942 UNITED STATES PATENT OFFICE FOLDING BOX De Forest Sackett, La Grange, 111. Application August 22, 1938, Serial No. 226,055

15 Claims.

The invention relates to folding boxes and more particularly to improvements in folding boxes of the general type which are fashioned from a single, suitably shaped blank of cardboard or other bendable sheet material.

The general object of the present invention is to provide a folding box of the type indicated wmcn, aitnougn requiring only a muumum or material for the blank, provides an unusually strong reinforcing structure for the vertical box walls and the comers between them.

A more specific object of the invention is to provide in a folding box of the type described a comer reinforcement construction embodying an integral flap or flaps interlocked with the side wall structure in such manner as to form a triple layer reinforcement at the box corner.

Another object of the invention is to provide in a folding box of the type described a comer and vertical wall reinforcement structurecomprised entirely of flaps or other parts integral with the box wall elements-so that no separate fasteners or strengtheners are required.

Still another-object of the invention is to provide a folding box of the type described embodying a strong multi-layer corner and side wall reinforcement in which the parts are snugly and smoothly fitted against the side walls to avoid unsightly protrusions.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying drawings in which:

Figure 1 is a partial planview of a blank for a folding box embodying the invention.

Fig. 2 is an enlarged detail perspective view, with some of the layers of material broken away, of one of the rear corners of a box fashioned from the blank of Fig. 1.

Figs. 3 to 7, inclusive, are partial perspective views of the box illustrating successive steps in the formation of the corner construction of Fig. 2, these figures being somewhat diagrammatic in form.

Fig. 8 is a partial plan view of a modified blank for a folding box embodying the invention.

Fig. 9 is an enlarged detail perspective view, with some of the layers of material broken away, of one of the rear corners of a box fashioned from the blank of Fig. 8.

Figs. 10 to 14 are partial perspective views of the box illustrating successive steps in the formation of the comer construction of Fig. 9, these figures being somewhat diagrammatic in form.

fled form of blank for a folding box embodying the invention.

Fig. 16 is an enlarged partial perspective view with some of the layers of material broken away, of one of the rear comers of a box fashioned from the blank of Fig. 15.

Figs. 17, to 20 are partial perspective views of the box illustrating successive steps in the formation of the comer construction of Fig. 16, these figures being somewhat diagrammatic in form.

Fig. 21 is a partial plan view of a blank for use in fashioning a folding box, embodying the invention, and illustrates particularly the front comer construction thereof which may be, if desired, used with the rear comer construction of Figs. 1 to 7. v.

Fig. 22 is an enlarged detail perspective view, with some of the layers of material broken away, of one of the front corners of a box fashioned from the blank of Fig. 21.

Figs. 23 to 26 are partial perspective views of the box illustrating successive steps in the formation of the comer construction of Fig. 22, these figures being somewhat diagrammatic in form.

In order to make clear the potentialities of the present invention several embodiments have been illustrated. These embodiments are, however, simply illustrative and by no means exhaust the possibilities of modifications. The appended claims are, therefore, not intended to be limited to the particular embodiments shown but, on the other hand, they are intended to cover all modifications and alternative constructions within the spirit and scope of the invention.

Referring particularly to Fig. 1, a folding box blank has been'shown therein which may be die-cut in the usual manner from a sheet of cardboard or other suitably bendable sheet material. Such material may be smoothly finished or coated on only one side. In the drawings, the coated or finished outer surface is unshaded and the uncoated inner surface is shaded. In this figure and in the others representing box blanks (Figs. 8, 15 and 21) the solid lines indicate the severed edges of various portions of the blank while the dotted lines indicate bending lines and along which the blank may be scored if desired to facilitate the bending operations. The box blank of Fig. 1 embodies a bottom "I, front and back walls II and I2 and end walls I 3 (only one of which is shown). The broader term "side walls," as used herein, is intended to embrace front and back walls as well as end walls the term being generally descriptive of any one of Fig. 15 is a partial plan view of another modithe series.

To strengthen the front and end walls II and I3, they are made of double thickness by folding the edge portions thereof in upon themselves. Accordingly, the end walls l3 include inner and outer wall sections IE! and I3", while the front wall ll includes inner and outer wall sections H and Il Rectangular tabs |3 on the edges of the inner wall sections 13 are bent to lie flat across the bottom l when the box is assembled (Fig. 2). A suitable top ll (Fig. 1) for the box is fashioned integral with the back wall l2 and may be provided with edge flaps l4" adapted to be inserted into the body of the box when the lid or top is closed.

A triple thickness of reinforcing material is preferably extended about the rear corners of the box to give maximum strength to the corners themselves, as well as to the back and end walls 12 and I3. The two rear comers are identical in construction and. consequently a description of one will suffice for both. Heavy reinforcement at the rear comer of a folding box is particularly desirable because of the likelihood of tearing at this point. Particularly heavy strain is exerted on the rear corner of the box when it is used for display purposes and in which case it is frequently picked up by the top or cover while the latter is in open position so that the whole weight of the box is suspended from the back wall, thereby tending to pull the end walls away from the back wall. Also, in removing articles from the box or placing them in it strain is placed on the corner as well as in other ways during its use. Reinforcement of the vertical walls themselves prevents their being crushed when a weight is placed on top of the box. The front comers are usually reinforced to a lesser degree than the rear corners, although the same triple reinforcement described for the rear corners can also be used for the front corners if desired. A front comer construction suitable for use on any of the boxes of Figs. 1, 8 and 15 is shown in Figs. 21 to 26, inclusive, and is hereinafter described in further detail. For the present, the description will be directed particularly to the reinforced rear corner construction.

Two integral flaps l5 and IE on the back wall l2 and the inner end wall section I3 (Fig. 1) are utilized in forming the novel corner construction contemplated. The flap I5 is comparatively short, while the longer flap I6 is made up of three sections I6, I6 and "5 defined by transverse scoring lines. The outer section It is curved to a point as indicated at I! (Fig. 1) while the irmer fiap section I 6 is notched at l8, for purposes which will hereinafter appear. No extra material is required to form the flaps I 5 and I6 since, in the initial formation of the blank, they lie within the border of a rectangular area embracing the wall and top portions of the box. In general, the flap l5 forms one layer of material extending across the carton comer and the longer flap, designated generally by the numeral I6, is threaded through an aperture or slit IS in the back wall I! and then doubled upon itself to form two additional layers of reinforcing material at the corner, so that the layers of connecting material between the end and back walls l3 and I2 total three when the corner is completed.

In assembling the blank of Fig. 1 into a carton or box the back wall I! and the outer section l3 of the end wall l3 are folded upwardly at right angles to the bottom "I (Fig. 3). When in this position the short corner flap I 5 can be pressed snugly against the inner face of the end wall section la The other end wall section I3 is then folded inwardly to overlie the flap l5 and frictionally grip the same, the tab l3 being pressed flat against box bottom It) (Figs. 2 and 4) After the flap l5 has been secured in position as described above, the flap I6 is threaded through the slit IS in the back wall (Fig. 4) and pulled through it until the flap section Hi lies smoothly against the inner surface of the back wall I2 (Fig. 5). The notch l8 in the edge of the flap section It receives the tab 13 on th end wall (Figs. 2 and 5) so that there will be no interference between these parts. The end section l6 of th flap I6 is then inserted between the inner and outer layers I3 and Iii of the end wall (Fig. 6) being tucked into position therebetween from the exterior of the carton (Fig. 6) so that the flap I6 is, in effect, doubled upon itself with the sections l6 and I6 lying snugly against opposite sides of the back wall l2 (Fig. 7). The generally pointed construction of the flap end section w (Fig. 6) facilitates the ready insertion of this flap section between the end wall sections. The inner and outer layers of the end wall l3 are thereby caused to grip the flap section l6 inserted between them, as well as the flap 15 to hold the same in position. If desired, tab IS on the end wall may be glued to the bottom of the box or held in position thereon by tongue 20 (Fig. 2) struck out from the box bottom.

With the reinforcing flaps arranged as described above, a strong and very rigid corner construction is achieved. By thus reinforcing the part of the box which is most frequently subjected to strain the entire structure may be made of lighter gauge sheet material so that a saving in over-all cost is accomplished. Furthermore, with the various layers of material all lying snugly against each other in the manner described there are no unsightly protrusions or bumps on the box surface.

A folding box embodying a modified form of triple reinforced corner construction has been shown in Figs. 8 to 14, inclusive. In this modifled construction the general outline of the carton blank (Fig. 8) is substantially similar to that of Fig. 1 and requires only the small amount of sheet material. Also similar are the two extra flaps, one short and one long, attached respectively to the back and end walls for forming the comer reinforcement. In the present instance, however, the long flap is threaded through the slit in the back wall from the outside of the box to the inside rather than in the opposite direction as in the case of the box of Figs. 1 to 7.

To identify parts of the partial blank shown in Fig. 8 the same reference numerals have been used for substantially identical parts as in Fig. 1. In particular th blank of Fig. 8 includes: a bottom II); a front wall, designated generally by the numeral II, and arranged to be folded upon itself to form inner and outer sections H- and II a back wall l2, having a cover I4 integral therewith; an end wall, designated generally by the numeral l3 and folded upon itself to form inner and outer sections I 3" and I3 together with an edge tab I3. Also, as in the previous case, a transverse slit or aperture I9 is cut in the back wall l2 to receive a reinforcing flap threaded through it. The ends of the inner end wall section It are out slightly shorter than outer section I3 so as to accommodate the folded flap structure in the assembled box.

The smaller of the reinforcing flaps, designated by the numeral 2| (Fig. a), is triangular in shape andis integral with the back wall I2.

The second or longer flap designated generally by the numeral 22 includes a triangular base portion 22, complemental with the triangular flap 2| and three rectangular sections 22', 22 and 22 arranged in alinement with the inner end wall section I3, although not united thereto. The intermediate flap section 22 is notched as indicated at 23 in order to receive the edge tab I3 on the end wall when the carton is assembled (Fig. 9) while the outer section 22 may be rounded to a point as indicated at 24 to facilitate its insertion between the inner and outer layers of the end wall I3 and through aperture I9.

In assembling the blank of Fig. 8 into a carton or box the back wall I2 and the outer section I3 of the end wall are folded upwardly at right angles to the bottom l (Fig. and the flap 2| is positioned against the inner face of the end wall section I3 so that it will later be pressed against the same by the inner section I3 when the latter is folded inwardly into position. The end wall section I3 is not folded in, however, until the second flap 22 has also been finally positioned.

The next step in the assembly operation is to fold the flap section 22 downwardly along the s'cored bending line 25 (Figs. 8 and 10) so that it overlies the flap section 22". The end of the flap 22 is then threaded through the slit IS in the back wall I2 (Fig. 11) and the flap pulled through to the full permissible extent so that the sections 22 and 22 lie snugly against the outer surface of the back wall I2 (Fig. 12).

The flap 22 is then, in efiect, doubled upon itself by pressing the section 22 against the opposite or inner side of the back wall 12; while the end flap section 22 is pressed against the inner face of the end wall section I3 (Fig. 13). Finally, the end wall section I3 is folded inwardly so that it overlies the -flap 2I and flap section 22 with the tab I3 pressed flat against the box bottom I0 (Figs. 9 and 14). In this manner the inner and outer layers of the end wall I3 are caused to grip the flap 2| and flap section 22 frictionally so as to hold the same securely in position. The tab I3 may be glued to the box bottom III or held in position thereon by a tongue 20 (Fig. 9) just as in the case of the box of Fig. 1. The end of the tab I3 fitting in the notch in the lower edge of flap 22 also holds the folded end wall in place (Fig.9).

Still another form of triple reinforcement for folding box corners, embodying the invention, is shown in Figs. to 20, inclusive. This construction is similar in most respects to that of Figs. 8 to 14, the principal difierence being that the maximum reinforcement is provided only at the upper end of the box comer rather than throughout its length. Such an arrangement finds particular utility in deep boxes. With the construction here under consideration maximum strength is provided at the upper end of the corner which is always the point most frequently subjected to unusual strains tending to tear the box walls apart. Moreover, the reinforcing flaps are so shaped that they aid in sustaining vertical load applied to the box side walls even though all of them do not reinforce the corner edge throughout its length.

The same reference numerals have again been used to identify substantially identical parts. Referring particularly to Fig. 15 the blank of sheet material therein shown comprises: a bottom III; a front wall, designated generally by the numeral II, and including inner and outer sections II and II adapted to be folded against each other; a back wall I2 having a suitable top or cover I4 integral therewith; end walls I3 including inner and outer sections I 3 and 13' adapted to be folded against each other and having a tab I8 on the edge of the inner section l3. The back wall I2 is again apertured or slitted at 26, but in this case the slit extends from the top edge of the back wall for only a portion of its width, rather than completely across the same.

The reinforcing flaps include a comparatively small flap 2'! integral with the back wall I2 and having a diagonal lower end, as well as a larger flap designated generally by the numeral 28. This larger flap 28 includes three sections 28, 28 and 28. It will be noted that the section 28 has a diagonal end complementing the diagonal end on the flap 21. Also, the outer end of the flap section 28 is rounded to facilitate its insertion through the aperture 26 in the back wall I2. The end of the inner end wall section I3 is notched in part of its edge to accommodate the folded flap structure in the assembled box.

To assemble the blank of Fig. 15 into box form the back wall I2 and the outer section I3 of the end wall I3 are folded upwardly at right'angles to the bottom Ill (Fig. 17) and the flap 2'I folded inwardly of the box structure so that it lies against the inner side of the end wall section I3. The flap 28 is then threaded through the slit 26 with the'sections 28 and 28 passed through it. By pulling the threaded flap 28 tight the flap section 28* is pulled snugly against the outer surface of the back wall I2 (Fig. 18). The next step in the assembly operation is to fold the flap 28 reversely upon itself so that the section 28 I lies flat against the inner side of the back wall I2 (Fig. 20) while the section 28 is pressed against the inner side of the end wall section I3. The end wall section I3 is then folded down so that its tab I3 is pressed flat against the box bottom III (Figs. 16 and 20). As in the previous cases the tab I3 may be held in position against the box bottom by a tongue 20.

With the reinforced corner construction assembled as described above it will be seen (Fig. 16) that three layers of sheet material extend about the upper end of the rear corner so as to solidly reinforce the same. Furthermore, the diagonal lower ends of the flap 21 and flap sec.- tion 28 extend all the way to the bottom end of the rear corner so that it is reinforced with two thicknesses of material throughout its length and furthermore is strongly reinforced to withstand vertical pressure which would tend to crush the box side walls. Any tearing strain tending to pull the back and end walls apart is resisted by the reinforcing flaps 21 and 28 which are integral respectively with the back and end walls and are, therefore, anchored at their opposite ends. This same feature is found in the two previous embodiments described above. Despite the fact that these reinforcing flaps do have portions overlying each other and projecting in opposite directions, nevertheless,

The three embodiments of the invention thus far described (Figs. 1, 8. and are particularly adapted to folding boxes having a top integral with the back wall, as it is not necessary for the wall containing the aperture or slot to be a double wall folded back upon itself. It is manifest, however, that each of the three embodiments can be used in the front corners of boxes similar to those described, or in the corners of a folding tray or folding telescope type box, simply by placing the slot in the outer front wall and folding the inner front wall into the box as the final operation of assembly. In Figs. 21 to 26,

however, another embodiment of the invention is illustrated which is particularly adapted for use at the front corners of boxes similar to those thus far described or to all the corners of a folding tray or folding telescope type box. The slot or aperture through which the reinforcing flap is threaded is placed in the inner front wall, thereby achieving greater ease of assembly and providing the same triple reinforcement but with none of the reinforcing construction visible on the outside of the box. This construction may, for example, be used at the front comers of the box blank shown in Fig. 1, and has been so illustrated.

The cardboard blank illustrated in Fig. 21 is substantially identical with that shown in Fig. 1, the principal difference being that the detail for the front corner section and front wall are illustrated in full in Fig. 21, although only partially shown in Fig. 1. As a means of reinforcing the front corner, a flap, designated generally by the numeral 29, is fashioned integrally with the outer section l3 of the end wall l3 (Fig. 21). A slot or aperture 33 is cut in the inner front wall section Il dividing it in effect into two parts, H and i I respectively. The third section of the front wall |l, which will press against the bottom of the assembled box, is integral with the central portion of the inner wall section II. The flap 29 is divided into three sections by suitable transverse scoring lines so that it comprises sections 29, 29 and 29. A smaller reinforcing flap 30 is fashioned integrally with the smaller inner front wall section II.

In assembling the blank of Fig. 21 to complete the front corner construction, the end wall section l3 and the front wall section Ii are bent upward from the bottom ill at right angles, and the larger inner front wall section ll folded inward so that the flap Ii rests snugly against the bottom of the-box where it can be held temporarily, or permanently held by gluing or a tongue 32 raised from the bottom of the box. Flap 29 is then folded inwardly against the inside of the front of the box (Fig. 23). In so doing, section 29 will overlap a triangular area 34 (see Fig. 22) of the inner front wall section H thus holding the inner front wall permanently in position. The next step is to press the remainder of the inner front wall ll" into position over the flap 2!! which operation also places the reinforcing flap 30 into its final position against the inside of the end wall section l3 (Fig. 24). In effect, the steps thus far have threaded the reinforcing flap 29 through the aperture or slot 33 (Fig. 24). Next the flap 29 is doubled upon itself so that the section 29* overlies the inner front wall section H and the section 29'is pressed against the flap 30 and the inside of the end wall section i3 (Fig. 25) Finally, the inner section l3 of the end wall I3 is folded inwardly upon section l3 and over the flap 30 and flap section 25 to the position shown in Fig. 26. It

will be noticed that the tab ll on the front wall is cut short so that the tab I3 on the end wall may fit snugly on the bottom across the entire width of the box (Fig. 22). As in the previous cases, the end wall tab l3 may be secured to the box bottom by gluing, or by a tongue 20, or by snugly fitting the end of the tab l3 into the crevice below the flap section 29 as indicated at 3| in Fig. 22. Again, the doubled end wall sections W and I3 in effect, hold all three of the reinforcing flaps in position. Three thicknesses of sheet material extend about the comer so that it is strongly reinforced. While one thickness does not cover the entire area of the comer (due to the portion of area taken by the flap 30 in the blank), it does provide reinforcement over its greater area, including the upper part where the strain is greatest.

For the sake of simplicity of description, the formation of the front and rear comers of the boxes has been described separately above. It will be appreciated by those skilled in the art, however, that in the actual formation of such a carton the front and rear corners at one or both ends of the carton will be formed substantially simultaneously. For example, in a carton provided with a rear corner construction like that of Fig. l and a front corner construction like that of Fig. 21, all of the necessary flap folding operations for both the front and rear comers are performed before the end wall section l3 is folded inwardly into its final position.

I claim as my invention:

1. A folding box fashioned from a blank of sheet material comprising a bottom having integral side walls along the edges thereof, at least one of said side walls being doubled inwardly upon itself at its upper edge to form a wall of double thickness, an integral flap on said one side wall bent at an angle to said wall to lie against the next adjacent side wall and doubled upon itself with the doubled portion of said flap extending across the comer between said one side wall and said adjacent side wall to form a double thickness reinforcement, the free end of said flap being held between the inner and outer layers of said one side wall.

2. In a folding box, a reinforced comer construction for uniting the ends of two adjacent sheet material side walls comprising, two reinforcing flaps integral with respective ones of said side walls, at least one of said flaps being doubled upon itself with the fold extending parallel to the box corner and with the doubled portion thereof extending across the box corner to provide a double thickness, said other flap extend ing across the box corner to provide a third layer at the corner, and means including a portion of only one of said side walls doubled upon itself for clamping and holding both of said flaps in position.

3. In a folding box, a reinforced corner construction for uniting the ends of two adjacent sheet material side walls comprising, two reinforcing fiaps integral with respective ones of said side walls and positioned to overlie each other and extend about the box corner in opposite directions to provide two layers of reinforcing material about the comer, and one of said flaps being doubled upon itself to form a third layer of reinforcing material extending about the corner.

4. In a folding box a reinforced comer construction for uniting the ends of two adjacent sheet material side walls comprising, two reinand one of said side walls having at least a portion thereof doubled upon itself and positioned to overlie the free ends of both of said flaps.

5. In a folding box a reinforced corner construction for uniting the ends of two adjacent.

sheet material side walls comprising, an integral flap on one end of one of said side walls, the other of said side walls having an aperture therein adjacent the corner between the walls, said flap having a portion thereof laid flat against one surface of said other side wall and said flap being threaded through said aperture and doubled upon itself so that a second portion thereof lies flat against the opposite surface of said other side wall.

6. In a folding box a reinforced corner construction for uniting the ends of two adjacent sheet material side walls comprising, an integral flap on one end of one of said side walls, the other of said side walls having an aperture therein adjacent the corner between the walls, said flap having a portion thereof laid flat against one surface of said other side wall, said flap being threaded through said aperture and doubled upon itself so that a second portion thereof lies flat against the opposite surface of said other side wall, and said one side wall being doubled upon itself to form a wall of double thickness with the free end of said flap positioned between the inner and outer layers of said double thickness wall.

7. In a folding box a reinforced corner construction for uniting the ends of two adjacent sheet material side walls comprising, an integral flap on one end of one of said side walls, the other of said side walls having an aperture therein adjacent the comer between the walls, said flap having a portion thereof laid flat against one surface of said other side wall, said flap being threaded through said aperture and doubled upon itself so that a second portion thereof lies flat against the opposite surface of said other side wall, a second flap integral with the end of said other side wall adjacent the comer and bent to lie in the plane of said one side wall, and said one side wall being doubled upon itself to form a wall of double thickness with the free ends of both of said flaps positioned between the inner and outer layers of said double thickness wall.

8. In a folding box a reinforced corner construction for uniting the ends of two adjacent sheet material side walls comprising, an integral flap on one end of one of said side walls, the other of said side walls having an aperture therein adjacent the comer between the walls, said flap having a portion thereof laid flat against one surface of said other side wall, said flap being threaded through said aperture and doubled upon itself so that a second portion thereof lies flat against the opposite surface of said other side wall, a second flap integral with the end of said other side wall adjacent the corner and bent to lie in the plane of said one side wall, and means for securing the free ends of both of said flaps to one side wall.

9. A folding box fashioned from a blank of sheet material comprising a bottom having integral side walls along the edges thereof, one of said side walls having a transverse slit therein adjacent a second side wall, said second sidewall having an elongated reinforcing flap integral with one end'thereof, a portion of said flap being laid against the inner surface of said one side wall, said flap being threaded through said slit and a second portion thereof laid flat against the outer surface of said one side wall, said second side wall being doubled upon itself to form a wall of double thickness, the free end of said flap being tucked between the inner and outer layers of said double thickness side wall.

10. A folding box fashioned from a blank of sheet material comprising a bottom having integral side walls along the edges thereof, at least one of said side walls being doubled upon itself with the edge portion thereof folded inwardly of the box to form a side wall of double thickness, a second side wall having a transverse slit therein adjacent said one side wall, a flap integral with the outer layer of said one side wall and being folded upon itself to lie against the outer surface of said second side wall, said flap being threaded through said slit and doubled upon itself with a second portion thereof lying flat against the inner surface of said second side wall and the free end being disposed between the inner and outer layers of said double thickness side wall.

11. A folding box fashioned from a blank of sheet material comprising a bottom having integral side walls along the edges thereof, at least one of said side walls being doubled inwardly upon itself at its upper edge to form a wall of double thickness, an integral flap on the upper edge of the next adjacent side wall folded inwardly against the inner surface thereof, a second integral flap on said one side wall bent at an angle to said wall to lie against the inner surface of said next adjacent side wall and doubled upon itself about said first named flap and with the doubled portion of said second flap extending across the corner between said one side wall and said adjacent side wall to form a double thickness reinforcement, the free end of said second flap being tucked between the inner and outer layers of said one side wall.

12. A folding box fashioned from a blank of sheet material comprising a bottom having integral side walls along the edges thereof, at least one of said side walls being doubled inwardly upon itself at its upper edge to form a wall of double thickness, an integral flap on the upper edge of the next adjacent side wall folded inwardly against the inner surface thereof and bearing on one of its edges, 9. second flap folded around the inside of the corner between said side Walls, a second integral flap on said one side wall bent at an angle to said wall to lie against the inner surface of said next adjacent side wall and doubled upon itself about said first named flap and with the doubled portion of said second flap extending across the corner between said side walls to form a double thickness reinforcement, the free end of said second flap being tucked between the inner and outer layers of said one side wall.

13. A folding box fashioned from a blank of sheet material comprising a bottom having integral side walls along the edges thereof, at least one of said side walls being doubled upon itself with the edge portion thereof folded inwardly of the box to form a side wall of double thickness, a second side wall'having a transverse slit extending only partially thereacrou and disposed adjacent said one side wall, a flap integral with the inner layer of said one side wall and having an elongated body part of a width narrower than said walls, said body part being folded so as to extend along the outer surface of said second side wall inwardly through said slit, and thence reversely along the inner surface of said second side wall. the free end of said flap being tucked between the inner and outer layers of said double thickness side wall.

14. A folding box fashioned from a blank of sheet material having bottom and side walls formed by edges of said bottom folded into upright position, characterized by the provision of a triple thickness corner reinforcement between at least two of said side walls, one of said thicknesses comprising a flap integral with one of said side walls and the other two thicknesses comprising a longer folded flap integral with the other of said side walls and extending around the box corner, and means integral with one of said side walls and holding both of said flaps in position to define the box corner.

15. In a folding box, a reinforced corner construction for uniting the ends of two adjacent sheet material side walls comprising, two reinforcing flaps integral with respective ones of said side walls, at leastone of said flaps being doubled transversely upon itself withthe doubled portion thereof extending around the box comer and the fold extending parallel thereto, and means including a portion of only one of said side walls doubled upon itself for holding both of said flaps in position.

DE FOREST SACKETT. 

